One of the most common medical applications for elongated, channel-assemblies is the use of a tube assembly for enteral feeding. Enteral feeding is the preferred method of providing nutritional support to the patient with a functional gastrointestinal tract. Enteral feeding has been proven to promote nitrogen retention, accelerate wound healing, and improve overall nutritional status. It is favored over intravenous feeding (total parenteral nutrition or TPN) because it helps to maintain intestinal integrity and has a lower infection risk. One of the major drawbacks to nasoenteral feeding, however, is the dislodgement of the tubes, the incidence of which has been documented to be 40 to 60%. The dislodgement of nasoenteral feeding tubes can have several negative repercussions:
(1) Nutritional support is interrupted, delaying wound healing and prolonging hospital stay.
(2) There is a substantial risk of aspiration pneumonia and respiratory failure when the tube is partially dislodged. In addition to the human suffering incurred with such a complication, expenses on the order of thousands of dollars per event per day are generated by antibiotic costs, intensive care and respiratory support. This complication is documented to occur in nearly one percent (0.8%) of the patients receiving a course of enteral nutrition.
(3) Replacement of dislodged nasoenteral feeding tubes is uncomfortable for patients and generates additional expenses due to physician and nursing time consumed, materials costs and procedural costs (including radiographic confirmation of tube placement).
(4) Caregivers may resort to intravenous nutrition which has a much higher risk of infection but is easier to secure.
(5) The above complications increase the risk of medical malpractice litigation.
The current trend in medicine towards managed care will also put pressure on hospitals to reduce complication rates, which will be tracked. Hospitals with excess complications will be excluded from contracts with large health care purchasers. Leaner staffing is also certain to be a byproduct of managed care. This means there will be less supervision of patients with feeding tubes. Not only will dislodgements increase in this setting, but they will be discovered later, making aspiration more likely. Replacing dislodged tubes will strain a lean staff even further.
Nasoenteral feeding maintains the dominant position in the nutritional support market due to its lower cost and incidence of infection relative to intravenous nutrition. Although most people can adapt to the presence of a small bore feeding tube once inserted, the actual placement is universally despised by patients. Nasogastric or nasojejunal intubation is often accompanied by retching, tearing, apprehension and verbal protests. Confused or combative patients strenuously resist tube placement requiring additional staff or restraint. This group of patients dislodge their feeding tubes with such regularity that the more easily secured parenteral route is often selected. By achieving a substantial reduction in the rate of inadvertent and uncooperative dislodgement, many of these patients could be successfully fed enterally.
Efforts to address this problem to date have focused on anchoring of the nasoenteral feeding tubes to resist patient removal. See, e.g., Sax, et al., "A Method For Securing Nasogastric Tubes In Unco-Operative Patients", Surgery, Gynecology & Obstetrics, May, 1987, pp. 471 and 472; McGuirt, et al., "Securing Of Intermediate Duration Feeding Tubes," The Laryngoscope, Vol. 90, 1980, pp. 2046-2048; Meer, "A New Nasal Bridle For Securing Nasoenteral Feeding Tubes", Journal Of Parenteral And Enteral Nutrition, Vol. 13, No. 3, 1989, pp. 331-334; and Meer, "Inadvertent Dislodgement Of Nasoenteral Feeding Tubes: Incidence And Prevention," Journal of Parenteral and Enteral Nutrition, Vol. 11, No. 2, 1987, pp. 187-189. The standard procedure involves taping the tube to the nose, but, as above noted, this procedure still is accompanied by the 40 to 60% removal or dislodgement rates. The additional use of wrist restraints or bulky mittens to deter inadvertent and uncooperative patient removal of the tubes has been frustrated by the "uncanny" ability of even confused patients to dislodge the tubes. The more drastic measures attempting to secure the tubes have included actual suturing of the tube through the nasal columella which can cause local infections and damage to the columella. Another approach is to use a "nasal bridle." Infrequent use of the nasal bridles is likely due to the numerous associated disadvantages. Placement of a nasal bridle requires from 10 to as much as 35 minutes of a skilled physician's time and can be quite difficult in uncooperative patients. Patient discomfort and the prospect of a patient injuring the nasal septum through vigorous tugging on the tube are also substantial drawbacks.
Removal, dislodgement or extirpation of medical channel-defining assemblies is not limited to enteral feeding tubes. Virtually any medical tube assembly which is mounted to a patient for an extended period of time for the administration of medicine, food or oxygen; the performance of medical procedures; or the drainage of fluids, can be dislodged either inadvertently by the caregiver during patient transport etc., or by confused, obtunded or otherwise uncooperative patients. Post-operative dislodgement of such tubes can be particularly serious, causing morbidity or even mortality.
One example of a traumatic medical tube assembly dislodgement problem occurs in connection with Foley-type urinary catheters. The Foley catheter is anchored in place by a balloon which is inflated once the end of the catheter is inside the bladder. Nevertheless, inadvertent and/or uncooperative patient dislodgements or extirpations occur in which the catheter is forcefully withdrawn through the urethra by the patient while the balloon is still inflated. This can cause the patient substantial discomfort and dangerous trauma with long-term effects.
Attempts recently have been made to prevent Foley catheter extirpation. A releasable connection has been suggested for use between the Foley catheter and the external drainage tube to the urine collection reservoir. This Foley disconnect assembly while representing a step forward, has several disadvantages. First, it is located at a substantial distance from the catheter's entry into the patient. Thus, even after disconnection, the uncooperative, obtunded or sedated patient still has an easily grasped catheter end, with a portion of the coupling thereon, which can be used to extirpate the catheter. Second, the Foley disconnect assembly is not designed to be secured externally to the patient and the coupling structure is essentially unidirectional, that is, the connection must be axially pulled to separate. Thus, if secured externally to the patient, for example by tape, the unidirectional coupling may fail to disconnect if the tubing is pulled in the wrong direction, resulting in possible pulling off of the securement device, dislodgement of the tubing and exposure of the patient to substantial stresses. If not secured, the coupling provides an easily gripped end on the tube assembly which the patient can use to extirpate the catheter. Moreover, the release force in the Foley disconnect assembly is sufficiently high that the connection would not be well suited for use in applications in which there was no balloon anchor on the catheter, for example, for enteral feeding tube applications.
Various other medical tube assemblies are known in the prior art in which connections or couplings have been interposed between an indwelling catheter and an external administering or drainage tube. Typical of medical tube assemblies having latched or locked couplings that can be manually released by a physician or technician are the devices of U.S. Pat. Nos. 5,137,524, 4,826,486, 5,047,021 and 4,338,933. Such assemblies have also included shut-off valves, for example, as shown in U.S. Pat. Nos. 3,707,972, 4,950,254 and 5,156,603, and others have included frangible elements and/or disconnection structures, as shown in U.S. Pat. Nos. 5,152,755, 4,834,706 and 4,294,247. Still further, many catheter-external tube connections are primarily concerned with the problems of making the connection or making a sterile connection, such as U.S. Pat. Nos. Re. 27,788, 4,511,163, 2,874,981 and 4,636,204.
Still further the problem of dislodgement or extirpation of elongated medical channel assemblies is not limited to tubing assemblies. In monitoring and/or stimulation applications, channel-defining assemblies are similarly positioned in patients and present problems of inadvertent or uncooperative dislodgement. Thus, inter-cranial pressure monitoring is accomplished through implanted transducers which communicate to external monitoring devices through electrical lines so that electrical signals can pass from the transducer through the conductor or channel to the monitoring device. A similar optical monitoring can occur based upon the use of fiber optic strands.
Despite the best efforts to address the problem of the dislodgement of medical channel structures, the solutions to date have been ineffective for the most part or potentially injurious. Patients with altered mental status are consistently able to pull on the tubes, lines and fiber strands and dislodge them and/or traumatize themselves.
Moreover, complicated and impractical "solutions" annoy the medical staff, generate extra costs and place patients all risk.
Finally, when a medical channel assembly is dislodged, it is commonplace for the blame to be placed on the nurse responsible for that particular patient. Deserved or not, such a rebuke adds to the aura of stress surrounding the procedure. The unpleasantness of the procedure, for both patients and hospital staff, the lost time, the associated expense (particularly in connection with surgical drains) and the possibility that it will have to be repeated, makes the reinsertion of medical channel assemblies a strongly disliked medical procedure.
Accordingly, it is an object of the present invention to provide a medical channel assembly and method which significantly reduces patient dislodgement, extirpation or removal and thereby reduces patient trauma and associated expense and medical staff stress.
A further object of the present invention is to provide a medical channel assembly and method in which the patient grippable portions of the assembly are easily disconnected without removal of the indwelling portion of the assembly, leaving a difficult to grasp indwelling length of the assembly in the patient.
Another object of the present invention is to provide an elongated medical channel assembly and method in which release or disconnection of the external portion of the channel from the portion internal to the patient can be easily accomplished at a wide range of angles with minimal force transmission to the sensitive tissues at the entry site.
Another object of the present invention is to provide a medical channel assembly which can have the external portion thereof easily disconnected by medical personnel, leaving an indwelling portion of the assembly which is substantially flush with the entry site into the patient so as to present less of an annoyance to the patient, allow greater mobility and to maintain patient dignity.
A further object of the present invention is to provide a medical channel assembly and method which can position an easy-disconnect coupling at virtually any location along the length of the elongated channel assembly in order to enable its location flush with the patient's entry site.
Still a further object of the present invention is to provide a medical channel assembly and method which is easier for medical staff to use, is safer for the patient, is inexpensive to manufacture, can include valves and filters, and is easily held in place as inserted in the patient.
The apparatus and method of the present invention have other objects and features of advantage which will be set forth in more detail in, or be apparent from, the following description of the Best Mode Of Carrying Out The Invention and the accompanying drawings.